The most upregulated neutrophil granule protein (Olfm4) in the MLN of MAP-infected mice at 6 weeks PI plays an important role in innate immunity against bacterial infection, and the most upregulated acute phase protein (Saa3) in the spleen suggested that MAP-infected mice at 6 weeks PI at an early stage of MAP infection along with Olfm4. This evidence concerns the gene OLFM4 and bacterial infectious disease.